drm/msm/dpu: calculate data_width like downstream

Derive INTF data_width from dce_bytes_per_line rather than
timing->width when DSC is enabled. Use DIV_ROUND_UP to avoid
rounding errors.

Signed-off-by: Alexander Koskovich <akoskovich@pm.me>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Tested-by: Pengyu Luo <mitltlatltl@gmail.com> # Lenovo Legion Y700 Gen4 (SM8750)
Patchwork: https://patchwork.freedesktop.org/patch/713333/
Link: https://lore.kernel.org/r/20260322-fix-data-width-calc-v2-1-d5f28136bc4e@pm.me
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
index 0ba777bda25351770edde2ffd7aea267a7be28e9..ba810f26ea3099106aac1783f7f6bf5e014e41a0 100644 (file)
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
@@ -10,6 +10,7 @@
 #include "dpu_formats.h"
 #include "dpu_trace.h"
 #include "disp/msm_disp_snapshot.h"
+#include "msm_dsc_helper.h"
 
 #include <drm/display/drm_dsc_helper.h>
 #include <drm/drm_managed.h>
@@ -136,6 +137,7 @@ static void drm_mode_to_intf_timing_params(
                timing->width = timing->width * drm_dsc_get_bpp_int(dsc) /
                                (dsc->bits_per_component * 3);
                timing->xres = timing->width;
+               timing->dce_bytes_per_line = msm_dsc_get_bytes_per_line(dsc);
        }
 }
 

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
index 7e620f59098499503813f11f330e6ec5d31d14b1..ac82b69aedf6b325f7beedd1ea06ffda414cbe38 100644 (file)
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
@@ -173,13 +173,29 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *intf,
        data_width = p->width;
 
        /*
-        * If widebus is enabled, data is valid for only half the active window
-        * since the data rate is doubled in this mode. But for the compression
-        * mode in DP case, the p->width is already adjusted in
-        * drm_mode_to_intf_timing_params()
+        * If widebus is disabled:
+        * For uncompressed stream, the data is valid for the entire active
+        * window period.
+        * For compressed stream, data is valid for a shorter time period
+        * inside the active window depending on the compression ratio.
+        *
+        * If widebus is enabled:
+        * For uncompressed stream, data is valid for only half the active
+        * window, since the data rate is doubled in this mode.
+        * For compressed stream, data validity window needs to be adjusted for
+        * compression ratio and then further halved.
+        *
+        * For the compression mode in DP case, the p->width is already
+        * adjusted in drm_mode_to_intf_timing_params().
         */
-       if (p->wide_bus_en && !dp_intf)
+       if (p->compression_en && !dp_intf) {
+               if (p->wide_bus_en)
+                       data_width = DIV_ROUND_UP(p->dce_bytes_per_line, 6);
+               else
+                       data_width = DIV_ROUND_UP(p->dce_bytes_per_line, 3);
+       } else if (p->wide_bus_en && !dp_intf) {
                data_width = p->width >> 1;
+       }
 
        /* TODO: handle DSC+DP case, we only handle DSC+DSI case so far */
        if (p->compression_en && !dp_intf &&

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
index f6ef2c21b66d42b364d436397264a5e9fee6bdd3..badd26305fc9456c1e794466c45e6f2e09cf519f 100644 (file)
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
@@ -35,6 +35,7 @@ struct dpu_hw_intf_timing_params {
 
        bool wide_bus_en;
        bool compression_en;
+       u32 dce_bytes_per_line;
 };
 
 struct dpu_hw_intf_prog_fetch {